The research proposed herein addresses itself to a comparison of normal and malignant cell plasma membranes. There are two major objectives involved in this study. (A) An in depth quantitative study of the relationship between Tissue Factor Activity and neoplasia and (B) A study of purified serum proteins their binding to cultured animal cells, and the effects these bound proteins have on cell surface mobility. A. Because (a) the coagulative activity of Tissue Factor appears to vary between normal and malignant cells, (b) there is a rapid biological assay for the activity, (c) the antigen(s) is located exclusively on the plasma membrane, and (d) the antigen(s) is easily purified, Tissue Factor represents an excellent tool for the study of variations occurring between normal and neoplastic cell surfaces. To date no study has sought to quantitate activity levels of this antigen(s) on cells of these two general classes. This study proposes methods of assessing, in a quantitative manner, the relationship between malignancy and Tissue Factor Activity. In addition, methods will be employed to determine if cells lacking the Activity still possess the Tissue Factor Antigen(s). B. Work in my laboratory has shown that isolated serum glycoproteins alter the growth characteristics of cells in culture, and affect the ability of these cells to bind plant lectins. A detailed study of these proteins, their binding to normal and tumor cells, and their effect(s) on cell surface mobility will form the second portion of this proposal. In addition, an effort will be made to screen serum from normal and tumor patients for the presence of these specific glycoproteins.